Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| escherichia coli f plasmid transfers to and replicates within legionella pneumophila: an alternative to using an rp4-based system for gene delivery. | derivatives of the self-transmissible f plasmid of escherichia coli can be introduced into legionella pneumophila by conjugation and maintained within only upon selection. in l. pneumophila. f-based replicons seem to exist as extrachromosomal elements since they were readily lost when f-containing l. pneumophila was grown on nonselective medium. the f-based plasmids were not self-transmissible in l. pneumophila. the mating defect may be due to an inability to form the f pilus since f-containing ... | 1994 | 7899513 |
| site-specific deletions of chromosomally located dna segments with the multimer resolution system of broad-host-range plasmid rp4. | the multimer resolution system (mrs) of the broad-host-range plasmid rp4 has been exploited to develop a general method that permits the precise excision of chromosomal segments in a variety of gram-negative bacteria. the procedure is based on the site-specific recombination between two directly repeated 140-bp resolution (res) sequences of rp4 effected by the plasmid-borne resolvase encoded by the para gene. the efficiency and accuracy of the mrs system to delete portions of chromosomal dna fla ... | 1995 | 7798149 |
| stability of r-microbes: stabilization of plasmid vectors by the partitioning function of broad-host-range plasmid rp4. | the genes for biosynthesis of the biodegradable polymer poly-beta-hydroxybutyric acid (phb) cloned from alcaligenes eutrophus h16 were used for synthesis of phb with recombinant escherichia coli strains. it was recognized that the phb-biosynthesis genes cause segregational instability to the plasmids used as vectors. recombinant phb-plasmids are rapidly lost from host cells and plasmid-free cells occur at high rates, even under conditions of selection for the plasmids. cloning the partitioning r ... | 1993 | 7763562 |
| bacterial conjugation mediated by plasmid rp4: rsf1010 mobilization, donor-specific phage propagation, and pilus production require the same tra2 core components of a proposed dna transport complex. | dna transfer by bacterial conjugation requires a mating pair formation (mpf) system that specifies functions for establishing the physical contact between the donor and the recipient cell and for dna transport across membranes. plasmid rp4 (incp alpha) contains two transfer regions designated tra1 and tra2, both of which contribute to mpf. twelve components are essential for mpf, traf of tra1 and 11 tra2 proteins, trbb, -c, -d, -e, -f, -g, -h, -i, -j, -k, and -l. the phenotype of defined mutants ... | 1995 | 7642506 |
| positive r plasmid mutator effect on chromosomal mutation to nalidixic acid resistance in nalidixic acid-exposed cultures of escherichia coli. | mutation frequencies to nalidixic acid resistance (15 mg/l in nutrient agar) were determined for derivatives of escherichia coli ab1157 carrying the mutator plasmids r46, r391 or pyd1, or the non-mutator plasmid rp4. frequencies of mutation remained constant in cultures of ab1157(r46) growing exponentially in drug-free broth, at a level about 12-fold higher than in the strain without plasmid. mutation frequencies in cultures of strains ab1157(r391) and ab1157(pyd1) were about three times greater ... | 1995 | 7592173 |
| the use of two-dimensional gradient plates to investigate the range of conditions under which conjugal plasmid transfer occurs. | gel-stabilized two-dimensional gradient plates were used to study the effects of ph, salt concentration and temperature on the conjugal transfer of plasmid rp4 between strains of escherichia coli and pseudomonas putida. the combinations of ph and salt concentration that permitted conjugation were mapped as a two-dimensional growth area occupied by transconjugants following conjugation. this conjugation domain was less extensive than the areas that supported growth of the parental strains, and sh ... | 1995 | 7582032 |
| new mini-tn5 derivatives for insertion mutagenesis and genetic engineering in gram-negative bacteria. | five mini-tn5 derivatives encoding resistance to km, cm, gm, tc, and sm, coupled with the polylinker of the pbluescriptii plasmid, were constructed. these derivatives are carried by an ampicillin-resistant plasmid that has a conditional origin of replication from plasmid r6k and origin of conjugal transfer from the broad host range plasmid rp4. the new vectors are smaller than those previously described and possess numerous unique restriction sites inside the minitransposons for gene cloning in ... | 1995 | 7497352 |
| comparison of kinetics of active tetracycline uptake and active tetracycline efflux in sensitive and plasmid rp4-containing pseudomonas putida. | membrane vesicles prepared from tetracycline-sensitive cells of pseudomonas putida took up tetracycline by an active transport system with an apparent km of 2.5 mm and a vmax of 50 nmol min-1 mg protein-1. in contrast, resistance determinant rp4-containing p. putida had an active high-affinity efflux system for tetracycline with a km of 2.0 to 3.54 microm and a vmax of 0.15 nmol min-1 mg protein-1. thus, the efflux system of tetracycline-resistant p. putida(rp4) had an average of 1,000-fold grea ... | 1982 | 7118827 |
| the orientation of transfer of the plasmid rp4. | 1982 | 7040167 | |
| [mobilization of vibrio cholerae chromosomal genes by plasmid rp4::mu cts62]. | the rp4::mu cts62 plasmid was constructed in escherichia coli cells and subsequently transferred by conjugation into the cells of vibrio cholerae. this plasmid had been shown to mobilize chromosomal genes of v. cholerae during intrageneric matings. the frequency of mobilization is higher in matings at 37 degrees c, the temperature which is semipermissive for temperature sensitive mu cts62 phage. this is only true for strains harbouring rp4::mu cts62, but not for strains containing the rp4 plasmi ... | 1982 | 7037543 |
| restriction mediated by pav2 affects the transfer of plasmids in acinetobacter calcoaceticus. | the naturally occurring plasmid pav2 restricts the entry of the p class plasmid rp4 and the w class plasmids r388 and s-a into acinetobacter calcoaceticus strain ebf65/65 from escherichia coli. the w class plasmids only transfer from e. coli into pav2-strains. plasmid rp4 is modified in the presence of pav2 such that it is no longer restricted on entry into pav2 recipients of strain ebf65/65. | 1980 | 7021765 |
| integrative compatibility: stable coexistence of chromosomally integrated and autonomous derivatives of plasmid rp4. | p group plasmid rp4 lambda att has a novel feature. its incompatibility function is phenotypically switched off when it integrates into the bacterial chromosome. | 1980 | 6991474 |
| [nature of the genetic control of antibiotic resistance in a pseudomonas aeruginosa bs205 strain]. | the clinical strain bs205 of p. aeruginosa is characterized by a high level of resistance to streptomycin, kanamycin, chloramphenicol, sulfanilamide and mercuric chloride. these markers can be transferred to p. aeruginosa pao by means of transduction with phage f116l or mobilization with plasmid rp4. in the same way as in the initial strain of p. aeruginosa bs205 no plasmid dna is detected in transducers or transconjugants. after transference to the strains of the transducers or transconjugants ... | 1982 | 6816141 |
| [integration of the genome of the mu-like pseudomonas aeruginosa bacteriophage d3112 into plasmid rp4 and its hybrid plasmid transfer into pseudomonas putida and escherichia coli c600 bacteria]. | the genome of a mu-like bacteriophage d3112 specific for pseudomonas aeruginosa was integrated in vivo into the rp4 plasmid. the fact of integration has been proved by two experiments: 1. the loss of rp4 plasmid is accompanied by loss of d3112 prophage; 2. transfer of the plasmid by conjugation from pseudomonas aeruginosa into bacteria of other species - p. putida pgg1 or escherichia coli c600 leads to the occurrence of clones of these species which liberate phage capable of growing on the lawn ... | 1982 | 6799358 |
| expression of e. coli genes carried by hybrids of plasmid rp4. | hybrids of the rp4 plasmid, containing bacteriophage mu and chromosomal genes of escherichia coli, were transferred into salmonella typhimurium, pseudomonas putida, pseudomonas aeruginosa and proteus mirabilis. the individual genes of the arginine, histidine, leucine and threonine operons were expressed in these microorganisms. | 1980 | 6777258 |
| naturally occurring plasmids exhibiting incompatibility with members of incompatibility groups i and p. | from a group of naturally occurring antibiotic resistance plasmids, a number of plasmids were identified which were incompatible with members of incompatibility group p and also incompatibility group i alpha or i gamma. these plasmids also exhibited strong entry exclusion with members of group p only and showed a host range which resembled that of plasmids of group i rather than those of group p. segregants of a number of these plasmids appeared to have lost some of the incompatability and/or su ... | 1980 | 6776095 |
| [features of incompatibility expressed by 1- and 2-replicon deletion derivatives of plasmid rp4]. | 1982 | 6754529 | |
| transfer of rhizobium meliloti psym genes into agrobacterium tumefaciens: host-specific nodulation by atypical infection. | the psym megaplasmid of rhizobium meliloti 2011 mobilized by plasmid rp4, or plasmid pgmi42, an rp4-prime derivative which carries a 290-kilobase psym fragment including nitrogenase and nod genes, was introduced into agrobacterium tumefaciens. the resulting transconjugants induced root deformations specifically on the homologous hosts medicago sativa and melilotus alba and not on the heterologous hosts trifolium pratense and trifolium repens. the root deformations were shown to be genuine nodule ... | 1984 | 6690420 |
| [effectiveness of plasmid rp4 mobilization of the bacterial chromosome in escherichia coli strains lysogenic for phages mu and lambda]. | the effect of phage lambda on mobilization of escherichia coli chromosome mediated by the mu phage and rp4 plasmid has been studied. the efficiency of bacterial chromosome mobilization is an order of magnitude lower than that in the control strain, monolysogenic for phage mu provided a termoinducible prophage lambda is located separately from mu. this efficiency is an order of magnitude higher in comparison with the control strain in case prophage is incorporated in the mu-lambda-mu structure an ... | 1981 | 6459264 |
| complementation analysis of the aliphatic amidase genes of pseudomonas aeruginosa. | a plasmid, pcl34, capable of autonomous replication in escherichia coli and pseudomonas aeruginosa has been constructed which carries the promoter and structural gene (amie) for p. aeruginosa amidase, but not the regulator gene (amir). plasmid pcl34 has been mobilized from e. coli to p. aeruginosa using the broad host range plasmid rp4. complementation studies were performed in p. aeruginosa strains carrying various amidase mutations. measurements of amidase activity in the recipients under indu ... | 1984 | 6440948 |
| [expression of the resistance genes of plasmid rp4 in escherichia coli cells grown by continuous cultivation]. | the resistance to tetracycline decreased in escherichia coli c600 cells containing plasmid rp4 and grown under the conditions of continuous cultivation. the population of cells containing plasmid rp4 is heterogeneous in the trait of tetracycline resistance, and most cells cannot grow in a selective medium with tetracycline at a concentration of 20 micrograms/ml. the decreased resistance to tetracycline was most pronounced for a glucose-limited chemostat culture and also in the presence of two pl ... | 1984 | 6429491 |
| [use of deletion mutants of plasmid rp4::d3112 for the genetic analysis of pseudomonas aeruginosa bacteriophage d3112]. | the hybrid plasmid rp4::d3112 becomes unstable in escherichia coli k-12 cells under certain growth conditions. the deletion mutants of this plasmid are formed at a high frequency. all the deletions selected have a specific feature: they start in the left end, at the point of joining of plasmid and phage dna, and remove different portions of the phage genome. the deletion mutants have been used for genetic mapping of d3112. we have localized the repressor gene ci (0-1.3 kb), 3 early genes (1.3-14 ... | 1983 | 6418616 |
| [changes in the nature of the cell growth of pseudomonas aeruginosa pao from the conjugative introduction of plasmid rp4]. | conjugative transfer of rp4 plasmid into pseudomonas aeruginosa pao at 30 degrees c results in inhibition of growth of plasmid-containing cells. no inhibition of growth of exconjugants takes place under special conditions (usage of minimal m9 medium or incubation at 42 degrees c) and when cells have specific mutations. these mutations were designated as rpm (rp4 maintenance). some of them render cells resistance to temperate phages of p. aeruginosa. the frequency of transfer of rp4 into pao1rpm, ... | 1983 | 6414887 |
| genetic manipulation of the restricted facultative methylotroph hyphomicrobium x by the r-plasmid-mediated introduction of the escherichia coli pdh genes. | the inability of hyphomicrobium x to grow on compounds such as pyruvate and succinate is most likely due to the absence of a functional pyruvate dehydrogenase (pdh) complex. further support for this was sought by studying the effect of the introduction of the escherichia coli pdh genes in hyphomicrobium x on the pattern of substrate utilization by the latter organism. these genes were cloned by in vivo techniques using the broad-host range conjugative plasmid rp4::mucts. plasmid rp4 derivatives ... | 1984 | 6393893 |
| [selection, analysis and mapping of mutations in the gene for resistance to kanamycin in plasmid rp4]. | we have tested possibilities of escherichia coli strains dependent on drugs streptomycin and paromomycin for selection of spontaneous mutations in the rp4 kan gene specifying resistance to aminoglycosids--kanamycin, neomycin and paromycin. a set of kan gene mutations were obtained, classified ad mapped. | 1984 | 6389260 |
| plasmid rp4 encodes two forms of a dna primase. | the pri gene locus of the conjugative broad host range plasmid rp4 maps between coordinates 40.3 and 43.5 and encodes two antigenically related forms of a dna primase with a molecular mass of 118 and 80 kda (kilodalton). genesis of these two products has been examined using pri+-recombinant plasmids. as shown by deletion analysis, the primase polypeptides are tow separate translation products which arise from an in-phase overlapping gene arrangement. it is suggested that transcription of a set o ... | 1984 | 6374382 |
| [transfer of plasmid rp4 into some phytopathogenic bacteria and its relation to their virulence]. | plasmid rp4 were transferred from escherichia coli into pseudomonas solanacerum, xanthomonas campestris pv. oryzae, x. campestris pv. campestris, and x. campestris pv. citri at the frequencies of 1.8 x 10(-6), 2.8 x 10(-6), 1.4 x 10(-2) and 2.0 x 10(-3), respectively. the frequencies of transfer depended on bacterial species and conjugation conditions. treatment of bromide at the concentration of 2 micrograms/ml and acridine orange at 100 micrograms/ml for 32 hrs the plasmid rp4 could be cured f ... | 1983 | 6342991 |
| proteus mirabilis chromosome mobilization by plasmid d: a physical characterization. | plasmid d, a hybrid of plasmids p-lac and r1 drd19, mediates polarized chromosome mobilization from one origin in proteus mirabilis strain pm5006, while the parental plasmids neither individually nor combined mobilize this chromosome. to elucidate its acquired mobilizing ability plasmid d was characterized physically in relation to p-lac and r1 drd19. restriction patterns of these plasmids were compared and it was shown that d consists of p-lac and only the r-determinant (r-det) of r1 drd19. a m ... | 1984 | 6327883 |
| molecular cloning and mapping of sphi restriction fragments of plasmid rp4. | a combined physical and functional map of plasmid rp4 is presented including the sites for 18 restriction endonucleases. several cleavage sites of sphi, bali, and apai are suitable for the dissection of the transfer gene regions. recombinant plasmids containing rp4 sphi fragments were constructed to assist in localizing sites relative to each other and to assign functions conferred by rp4 to the host. | 1983 | 6318250 |
| [transposition of the phage d3112 genome in escherichia coli cells]. | it has been demonstrated that the genome of phage d3112 of preudomonas aeruginosa can be transposed into escherichia coli chromosome as a component of the hybrid plasmid rp4 tcrkms::d3112. also, transposition of d3112 from e. coli (d3112) chromosome into rp4 plasmid occurs. the phage stimulates the chromosome mobilizing activity of rp4 plasmid, similar to other transposons. e. coli (rp4::d3112) cells were previously shown to form no colonies at 30 degrees c. auxotrophic mutants and mutants incap ... | 1983 | 6317518 |
| absence of cis-acting transposition immunity with tn7. | it is possible in two steps to insert into the plasmid rp4 two copies of the transposon tn7. this was demonstrated using a wild-type tn7 in the first step, and a tn7 derivative (carrying an additional marker), in the second step. the two successive transpositions occurred with the same polarity and frequency. the genetic structures of the resulting plasmids, predicted from the phenotypes of the bacterial host, were confirmed by direct analysis of the plasmid dnas. thus, the phenomenon of cis-act ... | 1983 | 6312476 |
| transposition of dna fragments flanked by two inverted tn1 sequences: translocation of the plasmid rp4::tn1 region harboring the tcr marker. | we have demonstrated the possibility of transposition of the plasmid rp4::tn1 fragment (21.2 kb) carrying the tetracycline resistance (tcr) gene and flanked by two tn1 copies. the new transposon, designated tn1756, bears lethal genes that kill host cells. therefore, its transposition can only be revealed in the presence of lethality-compensating helper regions of the plasmid rp4. thus, rp4::tn1 consists of two transposons, tn1755 (tn1-kmr-tn1) and tn1756 (tn1-tcr-tn1), sharing the tn1 sequences. ... | 1983 | 6307824 |
| [range of the transmissivity of the genetic transfer factors pap38, pap39, pap41 and pap42]. | a study was made of the transmissivity range of the genetic transfer factors pap38, pap39, pap41 and pap42 identified in e. coli. it was demonstrated that these factors are not capable of transfer to the cells of p. putida, p. fluorescens, r. leguminosarum, a. lipoferum, a. tumefaciens. factor pap42 is mobilized to transfer to p. putida and r. leguminosarum with the aid of plasmid rp4. it is assumed that in the course of mobilization, the cointegrative structures are formed between plasmids pap4 ... | 1983 | 6299434 |
| symbiotic nitrogen fixation: molecular cloning of rhizobium genes involved in exopolysaccharide synthesis and effective nodulation. | a transposon (tn5)-induced mutant (strain anu437) of rhizobium trifolii was isolated in which no water-soluble exopolysaccharide (eps) could be detected. this mutant was also incapable of forming nitrogen-fixing root nodules on clover plants. molecular cloning has demonstrated that the tn5 transposon was responsible for both of these mutant phenotypes and that there is a direct correlation between eps synthesis in this bacterial strain and its ability to carry out symbiotic nitrogen fixation. in ... | 1982 | 6296257 |
| tn292l, a transposon encoding fosfomycin resistance. | the determinant of resistance to fosfomycin of the serratia marcescens plasmid pou900 was transposed into the plasmid cole1 and into the plasmid rp4 in the absence of the reca function of the host. in each case, the acquisition of fosfomycin resistance was correlated with the presence of a discrete piece of dna, uniform in size and in restriction pattern, this new, 7.5-megadalton transposable element encoding resistance to fosfomycin has been called tn2921. a preliminary map of the transposon is ... | 1982 | 6282810 |
| occurrence of transposable trimethoprim resistance in clinical isolates of escherichia coli devoid of self-transmissible resistance plasmids. | fifty trimethoprim-resistant clinical isolates of escherichia coli, devoid of self transmissible trimethoprim resistance plasmids, were examined for the presence of trimethoprim resistance transposons. trimethoprim resistance was mobilized from 12 strains by transposition onto plasmid rp4. the trimethoprim resistance transposons isolated comprised two groups: those with and without linked streptomycin resistance. | 1982 | 6280601 |
| tn1 insertion mutagenesis in escherichia coli k-12 using a temperature-sensitive mutant of plasmid rp4. | a method for tn1 insertion mutagenesis in escherichia coli has been developed using pth10, a mutant plasmid of rp4 temperature-sensitive for maintenance. the mutagenesis involves three steps. firstly, from strains carrying pth10 showing resistance to the antibiotics kanamycin, tetracycline, and ampicillin at 30 degrees c but not at 42 degrees c, clones are isolated resistant to kanamycin at 42 degrees c. such temperature-independent, drug resistant clones probably carry pth10 integrated into the ... | 1981 | 6278248 |
| rna polymerase binding sites on the broad host range plasmid rp4. | binding sites of escherichia coli rna polymerase on rp4 plasmid dna were determined electron microscopically. comparison of the rna polymerase binding map and the genetic map of rp4 revealed several strong binding sites outside the well-known rp4 genes. rna polymerase binding sites for the three antibiotic resistance genes were also detected. two binding sites were observed for the tra-1 region, whereas the tra-2 and tra-3 regions showed no prominent affinity for rna polymerase. the genomic regi ... | 1981 | 6278054 |
| [migration of the ampicillin transposon in enteropathogenic escherichia]. | migration of tn 1 from plasmid rp4 into the chromosome of enteropathogenic escherichia (epe) of serogroups o124 and o111 was studied. e. coli k 12 lc 411 (rp4) was used as the donor. it was shown that the transposition rate markedly differed depending on the period of ;the cell isolation from tn 1 in the chromosome, i. e. during conjugation or after several subcultures of the transconjugants from the autonomic plasmid onto the selective media. during the conjugation process the migration rate of ... | 1981 | 6275775 |
| plasmid rp4 specifies a deoxyribonucleic acid primase involved in its conjugal transfer and maintenance. | we surveyed plasmids representative of most incompatibility groups for their conferred deoxyribonucleic acid (dna) primase activity. rp4 (incp) was one of the few with such activity although, unlike the derepressed incialpha plasmids (which also specify a primase), it did not suppress the dnag mutation. using deletion and tn7 derivatives of rp4, we located the presumed primase structural gene (pri) in the 37- to 42-kilobase region. tn7 insertions in the adjacent tra1 region also reduced or cause ... | 1981 | 6273381 |
| isr1: an insertion element isolated from the soil bacterium rhizobium lupini. | the insertion element isr1 was isolated from the soil bacterium r. lupini. in this strain, isr1 shows a very strong affinity to plasmid rp4. it causes rp4 mutations at the strikingly high frequency of 10(-2) to 10(-1), either by the integration itself or by generating deletions. in e. coli, isr1 seems to be inactive. no evidence could be obtained for a promoter site on isr1 or for an isr1-encoded protein. our results indicate, however, an isr1-specific termination signal for either transcription ... | 1981 | 6271495 |
| mutagenesis by insertion of drug resistance transposon tn7 into a vibrio species. | a halotolerant, collagenolytic strain of vibrio sp. was conjugated with an escherichia coli strain carrying plasmid rp4. the plasmid was transferred to and maintained in the vibrio and could be subsequently transferred in matings to suitably marked stains of the same species. after conjugation with an e. coli carrying the cointegrate plasmid rp4::mu cts61::tn7, vibrio transconjugants were selected that carried tn7 inserted into the bacterial chromosome. a large proportion of these transconjugant ... | 1981 | 6270064 |
| transposition of a dna fragment flanked by two inverted tn1 sequences. | the 32 md fragment (derived from plasmid rp4::tn1) carrying the kmr gene and flanked by two inverted tn1 elements is capable of reca-independent translocation to other plasmids. we designated this new transposon tn1755. in various crosses, frequencies of tn1755 transposition to plasmids co1b-r3, r15 and f'co1vbtrp varied from 2.5 to 90% of the frequencies of tn1 transposition. tn1755 can integrate into various sites of the recipient plasmids. we failed to observe transposition of another rp4::tn ... | 1981 | 6269963 |
| analysis of chromosome mobilization using hybrids between plasmid rp4 and a fragment of bacteriophage lambda carrying is1. | 1981 | 6267631 | |
| [induction of transposon tn1 translocation in uv-irradiated escherichia coli cells]. | ampicillin transposon tn1 translocates from plasmid rp4 into e. coli chromosome with a frequency of about 3.10(-4) per cell. irradiation of bacteria with uv-light increases the frequency of translocation essentially. mutation in lexa gene controlling the expression of cell uv-inducible functions blocks the induction of transposon translocation. protein synthesis inhibitor--chloramphenicol and transcription inhibitor--rifampicin decrease the effect of uv-light on transposition process. a possible ... | 1981 | 6265313 |
| bacteriophage mu-mediated gene transposition and in vitro cloning of the enterochelin gene cluster of escherichia coli. | transposition of chromosomal genes using bacteriophage mu has been used to obtain a partial order of the nine closely linked genes of the enterochelin-dependent iron transport system of escherichia coli k-12. fragments of the ent gene cluster were transposed into the conjugative plasmid rp4 and were characterized by genetic complementation. the partial gene order (entd, fes), entf, fep, entc, ent(abeg)...lip was derived using six plasmids which carried overlapping parts of the cluster, and the f ... | 1980 | 6260579 |
| transposition of tn 1 to the rhizobium meliloti genome. | a derivative of the incp1 plasmid rp4, carrying the thermoinducible prophage mucts62, was obtained in escherichia coli k12 j53 (rp4). it was impossible to maintain the hybrid plasmid rp4::mucts62 in rhizobium meliloti gr4. thus, it was used as a vehicle for introducing the ampicillin-resistant transposon tn1 into the r. meliloti genome. transposition of tn1 did not generate auxotrophic strains, suggesting that the insertion of tn1 into the r. meliloti genome was relatively specific. two chromoso ... | 1980 | 6258027 |
| [restriction and electron microscopic analyses of deletion derivatives thermosensitive with respect to maintaining plasmid peg1]. | temperature-independent deletion mutants of temperature-sensitive in self-maintenance plasmid peg-1, derived from r-factor rp4, are mapped using the restriction endonucleases psti, smai, ecori, bamhi and the heteroduplex analysis. the peg1 derivatives under study are found to have deletions in the area of ampicillin transposon tn1 and nearby genes. the left and the right ends of these deletions boundaries are localized between 37.5 md and 7.6 md in the rp4 map. thus far, the area of plasmid rp4 ... | 1980 | 6257589 |
| high frequency mobilization of the chromosome of escherichia coli by a mutant of plasmid rp4 temperature-sensitive for maintenance. | two mutants of plasmid rp4 temperature-sensitive for maintenance were isolated and one of them (pth 10) was extensively studied. cells carrying pth10 showed temperature-sensitive drug resistance from which we isolated a number of temperature-independent derivatives. almost all of them were hfrs donating chromosomal genes to recipient bidirectionally from different points of origin. the hfrs may be formed in two steps: (1) the transposon (tn 1) carried by pth 10 translocates into the host chromos ... | 1980 | 6255296 |
| adenine + thymine content of different genes located on the broad host range plasmid rp4. | the genetic map of plasmid rp4 was correlated with its adenine+thymine (at) map. for this purpose, rp4 dna was digested with one or both of the restriction enzymes ecori and hindiii and the resulting linear rp4 molecules and fragments were partially denatured, examined in the electron microscope and their at maps were determined using a computer program. from these at maps the ecori and hindiii restriction sites were located on the at map of rp4. since the positions of these restriction sites on ... | 1980 | 6248619 |
| isolation of transposon tna from plasmid rp4 carrying two copies of this element. | employing heteroduplex and restriction analyses, two inverted copies of a 3.2.10(6) dalton transposable sequence, tna, were found in rp4::tna, a spontaneously arisen derivative of the plasmid rp4. integration of the second copy of tna causes loss of the conjugative properties of rp4. both tna sequences in rp4::tna were localized and found to have opposite orientations. the dna fragment corresponding to the individual transposon tna was isolated after the endonuclease s1 digestion of rp4::tna mol ... | 1980 | 6244209 |
| replication defective rp4 plasmids recovered after chromosomal integration. | phh6000 is a composite replicon made by the in vitro ligation of the incp plasmid rp4 to a fragment of bacteriophage lambda capable of autonomous replication. derivatives were selected in which it had integrated into the escherichia coli chromosome by homologous recombination with the resident lambda prophage, and plasmids were subsequently regenerated from the integrated molecules. although of the same molecular size as phh6000, all had altered properties: those recovered from the chromosome of ... | 1984 | 6231650 |
| autoregulation of the tyrr gene. | strains of escherichia coli k-12 in which the transcription of lacz is initiated from the tyrr promoter have been constructed by use of the mu d (apr lac) phage of casadaban and cohen (proc. natl. acad. sci. u.s.a. 76:4530-4533, 1979). these strains have been used to examine the regulation of expression from the tyrr promoter, with the synthesis of beta-galactosidase used as an index of expression. the specific activity of beta-galactosidase fell to 51% upon introduction of lambda (tn10) tyrr+; ... | 1982 | 6120934 |
| transposon-mediated multiple antibiotic resistance in acinetobacter strains. | acinetobacter calcoaceticus subsp. anitratus, which is unusually resistant to multiple antibiotics, was the cause of an epidemic of respiratory tract infections in patients in an intensive care unit. a representative isolate of the epidemic strain was found to contain the aminoglycoside-modifying enzymes 3-n-acetyltransferase, 3'-phosphotransferase, and 3"-adenylyltransferase, which confer resistance to gentamicin, kanamycin, and streptomycin, respectively. in addition, the strain produced a cep ... | 1982 | 6100428 |
| involvement of kil and kor genes in the phenotype of a host-range mutant of rp4. | plasmid prp761 is a derivative of the promiscuous plasmid rp4, which has a tn76 insert 1.8 kb from its ecori site within the trfb region (barth 1979). this mutation was pleiotropic, having three effects: the plasmid is unstably maintained in e. coli, it reduces the growth rate of its host and it has suffered a reduction in host-range. we show that prp761 has reduced expression from both its kora and korb genes and that tn76 has inserted between them. fragment exchange experiments showed that thi ... | 1984 | 6097793 |
| high frequency mobilization of gram-negative bacterial replicons by the in vitro constructed tn5-mob transposon. | a dna fragment of the broad host range plasmid rp4 carrying the cis-acting dna recognition site for conjugative dna transfer between bacterial cells (mobsite) was cloned into the kanamycin-neomycin resistance transposon tn5. using conventional transposon mutagenesis techniques the new transposon, called tn5-mob, can easily be inserted into the host dna of gram-negative bacteria. a host replicon carrying tn5-mob is then mobilizable into any other gram-negative species if the transfer functions of ... | 1984 | 6094969 |
| [properties of potential vectors--derivatives of the broad-host--range plasmid rp4]. | nonconjugative deletion and recombinant derivatives of the rp4 plasmid are constructed. the plasmids can be used as vectors because they have relatively small molecular weights, unique cleavage sites for enzymes ecori, xhoi, bamhi, psti, kpni, bglii, salgi and hindiii (the plasmids prp401 and prp417 having six of these sites), and easily tested phenotypes (tcr, apr and gal+). in addition, all of them retain the broad host range property. also, the plasmid prp420 is a multicopy derivative capable ... | 1984 | 6094306 |
| [introduction of the hybrid plasmid rp4::d3112 into pseudomonas putida cells requires the presence of specific mutation in the phage genome]. | the wild type of d3112, a transposable phage of pseudomonas aeruginosa can not be introduced as a portion of the hybrid plasmid rp4::d3112 into pseudomonas putida cells. it is only possible when phage d3112 carries mutations designated lpc (lethal for p. putida and escherichia coli). analysis of heteroduplex molecules between dnas of phages d3112w+ and d3112lpc demonstrated the absence of nonhomology regions, which suggests that lpc is a point mutation. the lpc2 mutation was located within the i ... | 1984 | 6086454 |
| genetic and biophysical study of r plasmids conferring sulfonamide resistance in shigella strains isolated in 1952 and 1956. | the conjugative plasmids determining sulfonamide resistance in five shigella strains, each isolated from a different patient, have been characterized. one s. flexneri 2a strain, isolated in 1952, harbored an fi(+) plasmid of molecular weight 53 x 10(6), which specified synthesis of f-like pili and bore determinants for sulfonamide resistance (su) and bacteriocinogeny (col). this plasmid was compatible with plasmids of groups f(i), f(ii), i(alpha), and p. a second s. flexneri 2a strain isolated i ... | 1974 | 4215794 |
| [oxidation of n-alkanes by pseudomonas aeruginosa strain carrying the plasmid pbs251]. | pseudomonas aeruginosa pao8 cannot use n-alkanes or their respective alcohols as a sole carbon source. however, it can grow on n-alkanes when plasmid pbs251 is transferred into its cells. the hybrid plasmid pbs251 is a plasmid rp4 containing genes which control the capability to grow on n-alkanes of the c6-c12 series. studies of n-alkane oxidation by p. aeruginosa pao8 carrying pbs251 have shown that this plasmid controls the inducible alkane and alcohol oxidizing activities; the subsequent step ... | 1985 | 3937960 |
| [effective method of transduction with virulent phage pf16 using specific mutants of pseudomonas putida ppg1]. | a procedure of simple selection of pseudomonas putida ppg1 mutants is described. the mutants can be used for transduction with virulent pf16 phage, giving reliable results. the frequency of transduction of chromosomal markers ilv and trp was 10(-6). also, transduction of plasmid rp4 with phage pf16 was shown with the frequency of 10(-7). | 1985 | 3926609 |
| transfer of plasmid rp4 to myxococcus xanthus and evidence for its integration into the chromosome. | the broad-host-range plasmid rp4 and its derivative r68.45 were transferred to myxococcus xanthus dk101 and dz1; rp4 was maintained integrated in the chromosome. loss of plasmid markers occurred during the growth of the transconjugants, which could be prevented by selective pressure with oxytetracycline. the integrated plasmid was transferred back to escherichia coli often as rp4-prime plasmids carrying various segments of the m. xanthus chromosome. it also mediated chromosomal transfer between ... | 1985 | 3918015 |
| inhibition of conjugal transfer of r plasmids by nitrofurans. | nifurzide is a nitrofuran with antibacterial activity. as nitrofurans have been reported to interact with dna, we tested the ability of nifurzide to inhibit plasmid transfer. inhibition of plasmid transfer between escherichia coli strains was obtained for ten plasmids belonging to nine incompatibility groups. the same effect was observed when plasmid rp4 was harboured in six different members of the enterobacteriaceae. inhibition depended on the reduction of the -no2 group of nifurzide and was o ... | 1985 | 3906037 |
| trimethoprim resistance plasmids in escherichia coli isolated from cases of diarrhoea in cattle, pigs and sheep. | a total of 1572 isolates of escherichia coli obtained from the faeces of young farm animals with diarrhoea over the period 1980-1983 were screened for resistance to trimethoprim (tp). resistance to tp was detected in 263/954 (28%) of bovine isolates, 59/441 (13%) of porcine isolates and 15/177 (9%) of ovine isolates. seventy-five resistant isolates from separate outbreaks of infection on farms within a 25 mile radius of nottingham were examined in detail. sixty-eight (91%) of the 75 isolates wer ... | 1985 | 3897163 |
| [stability and dynamics of r-plasmids in escherichia coli populations in continuous cultivation]. | the stability of the conjugative plasmid rp4 and the nonconjugative plasmid pbs94 in escherichia coli c600 cells containing both plasmids was studied in continuous cultivation under chemostat and ph-stat conditions. the plasmids remained stable in the cells of the bacterial population for 100 generations, and no cells were found without the plasmids. the competition between strains with and without the plasmids in a mixed culture resulted in the removal of the plasmid-free strain from the popula ... | 1985 | 3892245 |
| mobilization of thiobacillus ferrooxidans plasmids among escherichia coli strains. | nonconjugative thiobacillus ferrooxidans plasmids were mobilized at high frequencies among escherichia coli strains by the incp plasmid rp4 and at low frequencies by the incn plasmid r46, but not by the incw plasmid psa. the mobilization region of a nonconjugative t. ferrooxidans plasmid was located on a 5.3-kilobase t. ferrooxidans dna fragment. | 1985 | 3890747 |
| expression of degradative genes of pseudomonas putida in caulobacter crescentus. | the recombinant plasmid rp4-tol was transferred into caulobacter crescentus at a high frequency, and the plasmid was maintained for at least 50 generations. c. crescentus cells which contained rp4-tol grew on all the aromatic compounds that the plasmid normally allowed pseudomonas putida to grow on. reciprocal transfers from c. crescentus donor to p. putida or escherichia coli recipients were less efficient and occurred at frequencies of approximately 10(-3). some representative tol-specified en ... | 1987 | 3597317 |
| molecular cloning of the plasmid rp4 primase region in a multi-host-range tacp expression vector. | plasmid rp4 primase was overproduced by utilizing autoregulated high-level expression vector systems in escherichia coli and in four other gram-negative bacterial species. analysis of the products in e. coli revealed that in addition to the two primase polypeptides of 118 and 80 kda the pri region of rp4 encodes two smaller proteins of 16.5 and 8.6 kda. the transcript for the four rp4-specified products is polycistronic. the vector system used in e. coli is based on the plasmid pkk223-3 (brosius ... | 1986 | 3549457 |
| lincomycin stimulates synthesis of tem-2 beta-lactamase by escherichia coli. | lincomycin increased the tem-2 beta-lactamase activity of escherichia coli k-12 cells carrying plasmid rp4 at a concentration which slightly inhibited cell growth. in a control culture beta-lactamase activity reached its maximal level in late log phase, whereas when lincomycin was present beta-lactamase activity continued to increase into the stationary phase. lincomycin (100 micrograms/ml) inhibited both cell growth and protein synthesis by about 35% but stimulated beta-lactamase activity 2.5-f ... | 1986 | 3530127 |
| role and specificity of plasmid rp4-encoded dna primase in bacterial conjugation. | the role of the dna primase of incp plasmids was examined with a derivative of rp4 containing tn7 in the primase gene (pri). the mutant was defective in mediating bacterial conjugation, with the deficiency varying according to the bacterial strains used as donors and recipients. complementation tests involving recombinant plasmids carrying cloned fragments of rp4 indicated that the primase acts to promote some event in the recipient cell after dna transfer and that this requirement can be satisf ... | 1986 | 3522540 |
| the association behaviour of beta-lactamases. sedimentation equilibrium studies in ammonium sulphate solutions. | the beta-lactamases (ec 3.5.2.6) from tem plasmid rp4, bacillus licheniformis 749/c and enterobacter cloacae p99 were studied in solution over a wide concentration range by equilibrium sedimentation. though crystal symmetries indicate that all three enzymes are potentially dimeric in their crystal forms, in 50 mm-sodium cacodylate at ph 6.5 the enzymes show only a small tendency to associate, indicated by a weight-average mr (mw) at 3% (w/v) concentration about 9% greater than that of the monome ... | 1986 | 3492196 |
| [isolation of the r'his plasmids of vibrio cholerae]. | v. cholerae strain vt5104 capable of donor activity in conjugation has been constructed by the genetic technique based on plasmid rp4::mucts62 integration into v. cholerae chromosome due to plasmid homology with mucts62 inserted into the chromosome. the gene for histidine synthesis has been mobilized and transferred into the recipient cells from vt5104 donor. the conjugants obtained are able to efficiently transfer his+ gene included into the plasmid structure in conjugation with eltor recipient ... | 1987 | 3474038 |
| [localization of structural genes of vibrio cholerae cholerae toxin using the recombinant plasmid rp4omega elt]. | the recombinant plasmid rp4 omega elt carrying escherichia coli heat-labile enterotoxin elt genes with 70-80% homology with genes vct of vibrio cholerae has been constructed. we used this plasmid to determine localization of the cholerae toxin genes vct on the map of vibrio cholerae cholerae. two types of the donors were revealed in matings of 10 strains of v. cholerae cholerae 569b/rp4 omega elt with the polyauxotrophic recipients rv31 and rv175: some strains had enhanced frequency of mobilizat ... | 1987 | 3319775 |
| [genetic determination of the vibriocinogenicity trait in vibrio cholerae of the el tor biotype]. | in two different strains of cholera vibrios two reca-dependent plasmids, pvib i (1.9-2.2 md) and pvib ii (5.2-5.8 md), have been detected. these plasmids determine the synthesis of vibriocin, coagulase and fibrinolysin, which has been established by the cotransformation of the dna of plasmids pvib i and pbr322 and by the transfer mobilization with the use of plasmid rp4. | 1987 | 3303760 |
| effects of lincomycin on synthesis of tem beta-lactamase by escherichia coli. | sub-inhibitory concentrations of lincomycin slightly inhibit growth of escherichia coli carrying plasmid rp4 and cause a 2-fold increase in tem-2 beta-lactamase. to analyze this effect, cultures were pulse-labeled with [3h]leucine, chased with non-radioactive leucine and immunoprecipitated with anti-beta-lactamase antiserum. the synthesis rate of beta-lactamase was two times higher in inhibited cultures than in control cultures. no significant decrease of labeled enzyme occurred during the 30 mi ... | 1988 | 3290174 |
| physical and functional mapping of two cointegrate plasmids derived from rp4 and tol plasmid pdk1. | cointegrate plasmids were formed in vivo between the broad-host-range r-plasmid rp4 and two catabolic plasmids derived from pseudomonas putida hs1. one of these was the wild-type plasmid pdk1 encoding the complete inducible toluene/xylene (tol) catabolic pathway and one was pdkt1, a deletion derivative of pdk1 selected after growth of hs1 on benzoate and supporting growth on only toluene. the two plasmids formed, pdk2 and pdkt2 respectively, each consisted of a complete rp4 replicon in which was ... | 1988 | 3076182 |
| transfer of the ti plasmid from agrobacterium tumefaciens into escherichia coli cells. | we have screened strains of agrobacterium tumefaciens for spontaneous mutants showing constitutive transfer of the nopaline ti plasmid ptic58 during conjugation. the ti plasmid derivatives obtained could be transferred not only to a. tumefaciens but also to e. coli cells. the ti plasmid cannot survive as a freely replicating plasmid in e. coli, but it can occasionally integrate into the e. coli chromosome. however, insertion in tandem of plasmids carrying fd replication origins (pfd plasmids) in ... | 1988 | 3049936 |
| cloning of the cyo locus encoding the cytochrome o terminal oxidase complex of escherichia coli. | the structural genes encoding the cytochrome o terminal oxidase complex (cyo) of escherichia coli have been subcloned into the multicopy plasmid pbr322 after the mu-mediated transposition of the gene locus from the bacterial chromosome onto the conjugative r plasmid rp4. introduction of cyo plasmids into strains (cyo cyd) lacking both terminal oxidases restored the ability of the strains to grow aerobically on nonfermentable substrates. strains carrying the cyo plasmids produced 5 to 10 times mo ... | 1987 | 3036778 |
| [structural-functional organization of r-plasmid pbs222 with a broad range of bacterial hosts]. | the broad host-range plasmid pbs222 is compatible with broad host-range plasmids of all known incompatibility groups and codes for tetracycline resistance. pbs222 is efficiently mobilized by inc p-1 plasmid rp4 and is also capable of conjugal transfer with low efficiency to different gramnegative microorganisms. the size of the plasmid (17.2 kb) has been determined and its physical map has been constructed. the plasmid harbours the unique sites for restriction endonucleases bglii, hindiii, hpai, ... | 1986 | 3027554 |
| [characteristics of derivatives of the plasmid rp4 in a broad range of hosts with altered properties of maintenance and inheritance]. | hydroxylamine-induced mutants of the plasmid ppd6 (8.4 kb) were isolated which are resistant to high doses of tetracycline. one of the plasmids studied--ppd21 is a multicopy mutant, another one, ppd12 is a dimeric form of the ppd6 plasmid. the ppd12 plasmid is very unstable, its derivative, ppd13 spontaneous mutant acquiring stability but not the ability to resolve dna multimeric forms into monomeric forms. multicopy bireplicon ppd619 plasmid was constructed by joining in vitro ppd6 and puc19 pl ... | 1986 | 3026896 |
| [characteristics of reca-independent recombination of plasmids in e. coli cells producing restriction endonuclease ecori]. | the restriction endonuclease ecori dependent recombination of compatible plasmids has been studied in reca cells of escherichia coli. plasmid rp4 and the isogenic cole1 type plasmids psa14 or psa25, differing in restriction-modification rm ecori genes, have been used to study this type of recombination. ecori dependent recombination of plasmids is demonstrated in reca cells and, thus, is independent of general system of homologous recombination. the classes of recombinant plasmids isolated from ... | 1985 | 3025706 |
| [plasmid recombination stimulated by restriction endonuclease ecori in vivo: formation of recombinant plasmids in reca+-cells of e. coli]. | the possible participation of restriction endonuclease ecori in recombination of compatible nonhomologous plasmids in e. coli cells has been studied. to study the process, plasmids rp4 and r245 have been transferred by conjugation into the recipient cells of e. coli harbouring one of isogenic plasmids, psa14 and psa25, different for the genes coding restriction endonuclease ecori. the genetic analysis of transconjugant phenotypes, coded by the plasmids, has permitted to register the recombinant ... | 1985 | 3025697 |
| [hybrid plasmid pbs251 containing genes for n-alkane degradation]. | the strain of pseudomonas aeruginosa bs316 utilizing h-alkanes of the c6-c12 series (alk+) harbours the 96 md plasmid pbs250. the use of plasmid rp4 to mobilize alk+ markers in conjugal transfer to pseudomonas aeruginosa and pseudomonas putida has resulted in isolation of transconjugants resistant to antibiotics (due to genes coded by plasmid rp4) and capable of growth on h-alkanes. a transconjugant from this series harbours plasmid pbs251, a derivative of plasmid rp4 containing the genes for oc ... | 1985 | 3025683 |
| [effective, plasmid rp4-dependent replication-transposition of dna of the transposable phage d3112 of pseudomonas aeruginosa in a heterologous escherichia coli system]. | the processes of replication and transposition of pseudomonas aeruginosa transposable phage d3112 in cells of escherichia coli (d3112) and e. coli (rp4::d3112) were studied. d3112 genome is a "silent cassette" ("conex-phage"--conditionally expressible) in e. coli cells incubated at 42 degrees c. two compulsory conditions for d3112 genome expression are incubation at 30 degrees c and the presence in cells of rp4 plasmid. processes of replication and transposition in e. coli are coupled. rp4 plasm ... | 1986 | 3021578 |
| [molecular cloning and functional analysis of dna regions of plasmid rp4 determining the incompatibility properties]. | sau3a-generated dna fragments determining incompatibility functions of the plasmid rp4 were cloned on the vectors ptk16 and pbr322. inc+ recombinant plasmids were divided into two types: 1) expressing incompatibility only towards the homologous rp4 replicon, 2) expressing incompatibility - both towards the homologous rp4 replicon and towards the heterologous replicons of plasmids r906 and r751. for one member of the first type plasmids it was shown that the cloned inc+-specific insertion derived ... | 1986 | 3021575 |
| [expression of pseudomonas aeruginosa phage transposons in pseudomonas putida ppg1 cells. ii. zygotic induction--a necessary condition for the formation of defective lysogens]. | the transfer of hybrid plasmid rp4::pt (where pt is the genome of a transposable phage specific for pseudomonas aeruginosa) into recipient cells of p. putida strain ppg1 occurs with the same frequency as into p. aeruginosa, the homologous host for pt. approximately 1/3 of all ppg1 exconjugants carrying rp4 markers lost the capability to produce viable pt phage. in contrast, in a cross with homologous recipient p. aeruginosa all exconjugant clones contained nondefective prophages in the hybrid pl ... | 1985 | 3002910 |
| transfer of transposable drug-resistance elements tn5, tn7, and tn76 to azotobacter beijerinckii: use of plasmid rp4::tn76 as a suicide vector. | transposable elements tn5, tn7, and tn76 were transferred to azotobacter beijerinckii. evidence was obtained for the transposition of tn5 but cells of the majority of presumptive transposition isolates had abnormal morphologies and rapidly lost viability when subcultured. data are presented that indicate that plasmid rp4::tn76 behaves as a suicide vector upon transfer to this host, allowing the isolation of a. beijerinckii::tn76 isolates at a high frequency. nitrogen-fixing mutants and leucine a ... | 1985 | 2999852 |
| f factor inhibition of conjugal transfer of broad-host-range plasmid rp4: requirement for the protein product of pif operon regulatory gene pifc. | by the use of deletions, point mutations, and gene fusions, we show that the protein product of the f factor pifc gene is responsible for f factor inhibition of plasmid rp4 conjugal transfer. deletion analysis of pif sequences carried by psc101-f chimeric plasmids demonstrated that removal of all or part of the pifc coding sequence greatly decreased or abolished the ability of these plasmids to inhibit rp4 transfer. amber mutations in the pifc gene eliminated inhibition in an su- host strain but ... | 1985 | 2993231 |
| genetic analysis of tn7 transposition. | the purpose of this work was to localize the dna regions necessary for the transposition of tn7. several deletions of tn7 were constructed by the excision of dna fragments between restriction sites. the ability of these deleted tn7s to transpose onto the recipient plasmid rp4 was examined. all the deleted tn7s isolated in this work had lost their transposing capability. the possibility of complementing them was studied using plasmids containing all or part of tn7. two deleted tn7s could not be c ... | 1985 | 2984518 |
| [interaction of yersinia pestis bacteria with bacteriophage mu]. | yersinia pestis cells are shown to be sensitive to bacteriophage mu cts62 infection. lysis of bacteria has been shown to be more efficient on solid nutrient medium than in lb broth. 10(-5) pfu per ml is the maximal concentration of bacteriophage particles yielded from the broth cultures of bacteria. moi 0.1 has been used to obtain such yields of bacteriophage. lysogenization of yersinia pestis cells has not been achieved when the standard methods of bacteriophage infection have been used. it was ... | 1985 | 2948125 |
| [transfer of prophage mu into methylotrophic bacteria in the plasmid rp4]. | bacteriophage mu genome has been transferred into the cells of pseudomonas methanolica and methylobacterium sp. skf240, that are naturally resistant to the bacteriophage, as a fragment of a hybrid plasmid rp4::mu cts62. temperature induction of the bacteriophage results in host cell lysis. plasmid rp::mu cis62 is maintained in methylotrophic cells presenting a cointegrative structure. the genetic and electrophoretic, analyses of the dna isolated from transconjugant cells have confirmed the concl ... | 1985 | 2948119 |
| [gene mutation and transfer caused by plasmid rp4::mu in vibrio cholerae]. | 1985 | 2943082 | |
| construction of transposons carrying the transfer functions of rp4. | the transfer genes and origin of transfer of the wide host range plasmid rp4 have been cloned into the transposons tn1 and tn5. the newly constructed transposons can be used to mutagenize bacterial plasmids or the chromosome in species such as escherichia coli or rhizobium. it is then possible to mobilize the plasmid or chromosome using the transfer functions provided in cis by the transposon. these constructs may aid chromosome mapping in many gram-negative species by allowing the wider use of ... | 1988 | 2854282 |
| transfer of incp plasmids into stigmatella aurantiaca leading to insertional mutants affected in spore development. | derivatives of the broad-host-range plasmid rp4, containing the wild-type or modified transposon tn5 were transferred by conjugation to various stigmatella aurantiaca isolates. the transposons and in some cases fragments of the plasmid as well were integrated into the chromosome. thus, insertional mutants have been obtained affected in spore formation in liquid culture. | 1988 | 2853291 |
| [sos-induction of the rp4 plasmid tet-determinant]. | induction of the tetracycline-resistance genes function by the inducer of the dna-repair and mutability sos-system, uv-light, has been tested. activity of the tet-genes residing on the plasmid rp4 in escherichia coli cells has been shown to be inducible by the low doses of tetracycline as well as by the mutagenic doses of uv-light. the induction was quantitatively registered by measuring the activity of beta-galactosidase of bacteriophage mud1 (ap, lac) inserted into the tet-genes of the plasmid ... | 1988 | 2848194 |
| [compatibility of transposable phages of escherichia coli and pseudomonas aeruginosa. i. co-development of phages mu and d3112 and integration of phage d3112 into rp4::mu plasmid in pseudomonas aeruginosa cells]. | the possibility of using a model system (which included rp4::mu plasmid and d3112 phage in pseudomonas aeruginosa cells) for analysis of compatibility of transposable escherichia coli phage mu and p. aeruginosa phage d3112, as phages and transposons, was studied. no interaction was observed during the vegetative growth of phages. the majority of the hybrid rp4::mu plasmids lost the mu dna after insertion of d3112 into rp4::mu. the phenomenon was not a result of transposition immunity. we conside ... | 1988 | 2840341 |
| mini-mulac transposons with broad-host-range origins of conjugal transfer and replication designed for gene regulation studies in rhizobiaceae. | novel mini-mu derivatives were constructed, carrying a truncated laczya operon fused to the terminal 117 bp of the mu s-end, for the isolation of translational lac fusions by mini-mu-mediated insertion mutagenesis. different selectable markers (chloramphenicol resistance; gentamycin resistance) were introduced to allow selection for mini-mu insertions in different replicons and bacterial strains. a mini-mulac derivative carrying the site for conjugal transfer of plasmid rp4 (orit) and the origin ... | 1988 | 2838383 |
| nucleotide sequence of the kanamycin resistance determinant of plasmid rp4: homology to other aminoglycoside 3'-phosphotransferases. | the kanamycin resistance determinant of the broad-host-range plasmid rp4 encodes an aminoglycoside 3'-phosphotransferase of type i. the nucleotide sequence of the kanamycin resistance gene (kmr) and the right end of the insertion element is8 of plasmid rp4 has been determined. the gene (816 bp) is located between is8 and the region (tra 1) encoding plasmid factors mediating bacterial conjugation. kmr and tra 1 are transcribed toward each other. the nucleotide sequence has been compared to five r ... | 1987 | 2832861 |
| mode of insertion of the broad-host-range plasmid rp4 and its derivatives into the chromosome of myxococcus xanthus. | the mode of insertion of the broad-host-range plasmid rp4 into the chromosome of myxococcus xanthus strain dz1 has been analyzed. the plasmid integrated in numerous sites of the chromosome and generated insertional mutations. there is a hot spot of integration located between 31.5 and 34.5 kb clockwise from the ecori site of the plasmid. in the absence of this segment the insertion can, however, take place, but much less efficiently. the presence of transposable elements on the plasmid decreases ... | 1987 | 2829249 |
| mini-mu transposition of bacterial genes on the transmissible plasmid. | using the prm30 plasmid, an aps deletion derivative of broad host range plasmid rp4 with integrated new minimu 5 (11 kb), we followed the transfer of escherichia coli chromosomal genes to the recipient strain. the minimu 5-mediated transposition of chromosomal genes occurs onto the plasmid with integrated minimu 5 rather than onto the "recipient" plasmid pnh602. the plasmid dna in recipient cells was detected by electrophoresis. one of the acquired hybrid plasmids ptb2 was analyzed genetically a ... | 1987 | 2826318 |